Electromagnetic mechanism.



No. 792,692. PATENTED JUNE 20, 1905. E. A. BUELL.

ELECTROMAGNETIC MECHANISM.

APPLICATION FILED mm. 9 1904.

INVENTEIFQ WI TNEESESP Earmmzanmeu aw/M 3y his Attorney UNITED STATES Patented June 20, 1905.

PATENT OEEIcE.

EDWARD A. BUELL, OF DEKALB, ILLINOIS, ASSIGNOR TO SELECTIVE SIGNAL & TELEPHONE MANUFACTURING CO, OF SYOAMORE, ILLI- NOIS, A CORPORATION OF ILLINOIS.

ELECTROMAGNETIC MECHANISM.

SPECIFICATION forming part of Letters Patent No. 7 92,692, dated June 20, 1905.

Original application filed May 2, 1904, Serial No. 205,876. Divided and this application filed August 9, 1904. Serial No. 220,118.

To (l/ZZ whom it may concern:

Be it known that I, EDWARD A. BUELL, a citizen of Canada, residing at Dekalb, in the county of Dekalb and State of Illinois, have invented a certain new and useful Improvement in Electromagnetic Mechanism, (being a division of my application, Serial No. 205,876, liled May 2, 1904,) of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to electromagnetic apparatus, and is of particular service in the operation of switching mechanism. In practicing my invention I impart to the armature of a single electromagnetic organization a greater number of motions than have been imparted to the same hitherto.

In the preferred embodiment of the invention a pivotally mounted armature is employed whose pivot is adapted for bodily movement by the armature, about which the armature not only rotates, but is adapted for complete bodily movement therewith.

In practicing my invention I employ a contrally-pivoted armature which is adapted to oscillate or rotate in opposite directions and which is adapted for movement with its pivot.

In the preferred organization there is employed an electromagnet having two core branches, each desirably supporting or carrying a helix, said core elements being preferably upon the same side of the armature that is common thereto. The mounting for the pivot is desirably confined to straight-line travel by having a plunger-and-socket guiding action, though I do not wish to be limited to any very peculiar characteristics of construction that have entered into the preferred embodiment of the invention.

The device of my invention is of particular service in the operation of the selective-signal-controlling apparatus at the substations of a party telephone-line, it having been of special utility in setting, locking, and releasiug an associated circuit-controlling wheel,

the armature in moving in one direction serving to set the wheel, when moving in another direction serving to lock the wheel, so that wheels at other stations can be moved without disturbing the adjusted position, and serving to release its associated wheel to restore the apparatus at this substation to normal conditions when subscribers are through with their conversation. I have therefore shown the particular adaptation of my invention to use in connection with party telephone-lines; but I do not wish to be restricted to any particular use that the device of my invention may be put.

I will explain my invention more particularly by reference to the accompanying drawings, in which Figure 1 illustrates a party telephone-line and so much of an apparatus at an exchange as is necessary to an understanding of my invention. Fig. 2 is a front view showing the relation of the coils and armature. Fig. 3 is a view on line (1/ a of Fig. l of the electromagnetic portion of the structure.

Like parts are indicated by similar characters of reference throughout the different figures.

In order that the specific application that I make of my present invention may thoroughly be understood, I will first describe in detail the telephone system to which it has been applied.

At the exchange I have indicated line-jacks 1 and 2 of normally independent telephonelines, there being a cord connecting apparatus for uniting independent telephone-lines in conversation, such cord connecting apparatus including an answering-plug 3 and a connecting-plug at, which cord circuit has the usual associate apparatus, including, among other things, (not shown,) an operators telephone outfit 5, an operators ringing-generator 6, a listening-key 7, and a ringing-key 8, there being provided a common actuating-lever 9, whereby the springs of the listening-key may be pressed against the operators telephoneterminals and whereby the springs of the ringing-key may be removed from their normal contacts and brought into engagement with the alternate contacts which constitute the ultimate terminals of the ringing-generator 6. Both of the alternate contacts of the ringing-key 8 are thus used when the bells to be rung by the generator are in metallic connection only with the telephone-lines.

I have indicated grounded signal receivers or bells 10 at the substations, which are connected with the sleeve side of the party telephone-line 11, and I hence preferably provide asupplemental key 12, which is operated to limit the current emanating from the generator to the sleeve side of the telephone-line, the circuit being completed by way of the grounded alternate contact of the key 12 and the grounded bells. I, however, do not wish to be limited in all embodiments of my invention to the use of the grounded bells. I have indicated upon the party telephone-line three stations A, B, and C, though the number of stations connected with the line may be varied. The various stations are connected in multiple or bridge between the sides of the party-line, station A being included in such a bridge 13 14, while station E has a bridge-path 15 16, while station Chas a bridgepath 17 18. I prefer the bridge arrangement, as the element of impedance is so largely removed, though I do not wish to be limited to such an arrangement. The apparatus at station B is illustrated in detail. The apparatus of the other stations is preferably similar thereto. At station B, I have illustrated as one type of substation outfit a gravity tele .known magneto-generator at the substation B; but I do not wish to be limited to the use of magneto-generators at subscribers sta tions. The magneto-generator 22 when operated serves to release the shutter of the line-indicater 23, which in this particular instance is grounded and is normally in connection with the sleeve side of the party-line and the generator by way of the long spring of the line-jackl and the contact engaging said spring when the jack is free of a plug. In order that the current from the generator 22 may be-sent in sufficient volume over the line to operate the line-indicator, the bell 10 is preferably made of very high resistaucefor example,one thousand ohmswhieh,however,

is not too great to permit a fraction of the current to be diverted from the circuit containing the line-indicator through the bell to have the same operated at the calling-station, said bell being in shunt relation with the generator. 7

Either or both of the branches 15 and 16 may be subject to the electrical control had by the device of my invention. I have shown both sides 15 and 16 to depend for their continuity upon a movable circuit-changer 24, desirably in the form of a ratchet-wheel, said ratchet-wheel carrying or operating two contact elements, each mechanically subdivided into two parts 25 and 26 and 25' and 26' insulated therefrom, the parts of each set of elements being desirably constructed in two mechanically-separated but electrically-connected elements which preferably are in the form of pins, though I do not wish to be limited to a contact element of this form. When the ratchet-wheel is in its initial or normal position, the elements 25 and 25 are in electrical connection with riders 27 27, which in turn are connected with and constitute parts of conductors 15 and 16. The elements 25 26 and 25 26' are separated by distance corresponding to distances between varying numbers of teeth at the different stations. The pins 25 and 25 at each station are what might be termed the normal or zero contact elements. The normal or Zero elements 25 and 25 at each station are those contact elements which are always directly engaged by the riders 27 27 at all of the stations when the lineis idle, which engagement is to be maintained when the line is to be used as an ordinary partyline. The elements 26 26 may be termed the alternate contact elements and are those elements which are directly engaged with the riders 27 27 at any selected station when secrecy is desired and where selected signaling is to be practiced.

In placing two subscribers on the same line in secret connection the operator intermittently actu ates the electromagnetic apparatus, to be hereinafter described, for the purpose of shifting the circuit-changer 24 until the proper elements 26 26 (which, as hitherto set forth,are located differingdistances away from the elements 25 25, according to the different stations) are brought into direct engagement with the riders 27 27 at the stations between which the secret connection is to be established. For example, stationB indicates the second station upon the line, station 0 may indicate the third station, and station A the first. At station A the pins 25 25 and 26 26 preferably have no tooth intervening. At

station B the pins 25 25 and 26 26 have one tooth intervening, and at station 0 the pins 25 25' and 26 26 have two teeth intervening. To connect station B with station 0, for example, the operator shifts thecireuit-changer 24 two steps and then locks the same by magnetic metal.

mechanism to be set forth and shifts the circuit-changer 24 at station C another step, the said latter circuit-changer having previously been operated two steps in setting the apparatus at station E. It will be apparent to those skilled in the art that at all other stations the riders 27 27 are not in connection with those portions of the circuit changers or wheels 24 that are electrically connected with the teeth 25 25 and 26 26, thereby opening the branches that depend for their continuity upon the engagement of the riders 27 27 with one or the other of the teeth 25 25 and 26 26'. Thus both terminals of the telephone-receivers are disconnected from the line by being ineluded in open circuit.

Having described one form of circuit-changing apparatus that may be employed in connection with my invention for governing the association of the subscribers stations with the party-line, I will now describe my improved electromagnetic mechanism that is employed for effecting the operation of the said circuit-changers and will thereafter describe the switching apparatus at the exchange that is employed for operating the electromagnetic mechanism.

The wheels 24 are provided with coil-springs 28, by which when released by my magnetic actuating mechanism they are restored to initial positions, where the contacts 25 25 engage the riders 2'7 27, the wheel 24 at station B having thereon an arm 29, engaging a stop 30 to limit the return of the wheel. My improved electromagnetic mechanism has two spools or helices 31 32, preferably unprovided with a magnetic yoke, but having a common armature 33 centrally pivoted between the poles of the spools. The magnet of this mechanism is provided with a permanent magnet 34 to induce polarities of the same sign in the poles of the coils 31 32 that are presented to the armature 33 and to also polarize said armature. One of the windings, as the winding 3.1, when included in circuit with the source of direct current tends to reinforce or increase the field at the pole of said winding 31 opposed to the armature 33, while the other winding is reversely wound to secure an opposite effect. By proper circuit eonneetions the armature 33 may be caused to oscillate in a clockwise direction or in a countor-clockwise direction, as desired, or the armature may be bodily moved toward both opposing poles. The pivot for the armature is desirably provided upon a plunger 34, that has splined engagement with a housing 35, the parts 34 and being desirably of non- The pivot is preferably subdivided into two parts 36 37, the bracket 38,

carried by the plunger 34, serving to support these pivots, the parts of the bracket that immediately support the pivots being preferably of ear-like formation, the armature 33 being interposed between these cars. Some suitable means may be provided for normally maintaining the armature away from both poles. I have indicated retractile springs 39 39 and adjustable back-stops 40, against which the armature is normally held by said retractile springs. The work to be performed by this electromagnetic mechanism may be accomplished by some suitable extension of the armature-as, for example, the rod or lever 41, projecting at right angles to the armature. I consider the electromagneticmechanism just described to be broadly new with me, irrespective of what it is adapted to. In the present instance this electromagnetic mechanism has been applied to the peculiar form of secrecy and cut-out. switching mechanism that has been hitherto described. The first function that this mechanism has to perform is the movement of the circuit-changing wheel 24 from engagement with its normal stop 30, to which end the armature 33 is attracted toward both of the magnet-poles opposing the same. This movement causes the dog 42, pivotally supported upon the arm 41, to advance the ratchet-wheel against the force of the coilspring 28. The next function of the magnetic mechanism is to lock the circuit-changing wheel 24in the selected position. This is accomplished by causing a rotation of the free end of the arm 41 downwardly by the counter-clockwise movement of the armature, so that the cam 44 may be pressed against the plunger 45 against the force of a coil-spring 46, whereby a pin 47, carried upon the wheel, may be forced into engagement with the hooked end of the plunger 45, which desirably is sufiiciently yielding, so as to permit the said hooked end to pass the pin 47, but which is of such a nature as to secure a locking engagement until the engagement between the pin and plunger has been broken. As the dog 42 moves the wheel in a counter-clockwise direction, the locking-1i awl or (ilog4S, having a fixed axis of rotation at its rear end, prevents the return of the wheel, which locking-pawl is pivoted upon a link 49, that may be moved back and forth in an inclined groove in an enlarged end of the arm 41. It will be seen how effectively the two elements 48 and 45 serve to define the position of the wheel 24, the first preventing movement by the spring and the second, when set, preventing movement of the arm 41 and the armature 33 in a direction parallel to the cores of the magnet. It will be understood that the plunger 45 need only be operated at the station where the circuit-wheel 24 is to be moved the lesser number of times in effecting telephonic communication between that station and another where the circuit-wheel is to be moved a greater number of times. Such movement of the circuit-Wheels, as is understood, is only to be had when secrecy is desired, so that the subscribers may call each other or the exchange without the aid of my improved electromagnetic mechanism. When it is desired to release a given circuit-wheel, the armature 33 is moved in a clockwise direction, whereby the dog 48 is lifted, permitting the spring 28 to move the wheel 24 back against its stop 30. When this movement occurs, the plunger 45 is free from the pin 47, whereupon the spring 46 restores said plunger to its initial or normal position. The various operations of the magnetic circuit-controlling mechanism at each station may be governed by a battery 51, divided into two parts for some purposes, but all of which are used for the purpose of effecting the bodily reciprocation of the armature 33. The extreme poles of this battery are connected with the alternate contacts of the selecting-key 52, the springs whereof are thrust against said alternate contacts when selection at the substations is to be effected. The lever of the key 52 is preferably maintained toward the right, while the wedge end of the lever 9 is moved to and fro to intermittently effect the connection of the springs of the key 8 with their alternate contacts that are in electrical connection with the springs of the key 52, whereby the battery 51 is intermittently in brildge of the party-line for the purpose specifie I have found by experiment that one-half of each battery will not be sufficient to eflect bodily reciprocation of the armature 33, but will effect the operative energization of one coil of the magnet only. The left-hand end of the battery 51 is preferably employed for operatively energizing the coils 31 32 independently, depending upon the direction that the current from this portion of the battery is impressed upon said windings, such current being insuflicient to operatively energize both windings in a manner to effect the bodily reciprocation of the armature 33, but sufliciently increasing the magnetization at one of the poles opposed to the armature 33 and weakening the other to secure the oscillation of said armature in one direction or the other, according to the direction of the current. The poles of this half of the battery are connected with the springs of the key 53 when said springs are thrust against their alternate contacts that are connected with said poles, the plunger 54 being employed for effecting this movement of said springs. Gurrent from the left half of the battery 51 is thereupon caused to flow over the line in a direction to reinforce the magnetization of the core of the winding 32 and to oppose or weaken the magnetization of the core of the winding 31, whereupon the armature 33 is rocked in a counter-clockwise direction to effeet a depression of the plunger 45 into engagement with the pin 47. When it is desired to restore the individual mechanisms to their initial positions at the substations, the 5 locking-key 53 is released and the springs of the releasing-key 55 are spread apart by their associate lever, whereupon the left-hand half of the battery 51 has its connection with the line reversed, causing a reversal of the conditions just described respecting the energization of the cores of the windings-31 32, forcing the armature 33 to turn in a clockwise direction and thereupon elevate the dog 48 to permit the spring 28 to restore each circuit-wheel against its stop 30.

While I have herein particularly set forth one adaptation of my improved electromagnetic magnetism, I do not wish to be limited thereto, nor do I wish to be limited to the precise details of construction set forth, as changes may be made without departing from the spirit of my invention; but,

Having thus described my invention, I claim as new, and desire to secure by Letters Patent, the following:

1. An electromagnetic mechanism having a swinging armature that may swing under the influence of the magnetic elem ent,and amounting for the armature that is free to move with the armature through the influence of the magnetic element whereby the said armature may be bodily moved, substantially as described.

2. A circuit-changing mechanism including an electromagnet having a circuit-controlling armature adapted to be oscillated and also to be bodily moved by the field of the magnet, substantially as described.

3. An electromagnetic mechanism having a swinging armature that may swing under the influence of the magnetic element, and a mounting for the armature that is free to move with the armature through the influence of the magnetic element whereby the said armature may be bodily moved, the said electromagnetic element presenting two poles to the armature, one pole serving to effect movement of the armature in one direction, the other pole serving to effect movement of the armature in another direction, while both poles serve, in conjunction, to effect bodily movement of the ar- 7 mature, substantially as described.

4. An electromagnetic mechan sm having a swinging armature which is also bodily mov' able, said electromagnetic element presenting two poles to the armature, one for moving the armature in one direction, the other for moving the armature in another direction, the two poles, when acting in conjunction, serving to effect bodily movement of the armature, substantially as described.

5. An electromagnet comprising two helices, an armature pivoted between the helices, a bodily-movable mounting for the armature, and spring mechanism acting upon said mounting normally maintaining the armature away from said helices, substantially as described.

6. An electromagnetic mechanism possessing two helices, a bodily-movable armature action of both helices thereupon, substantially presented to the said helices, and spring meehas described. IO anism acting upon the armature, normally In Witness whereoflhereunto subscribe my maintaining the armature away from said heliname this 23d day of July, A. D. 190%.

5 oes but permitting the said armature to be EDWARD A. BUELL.-

moved in one direction by one helix and in an- \Vitnesses: other direction by the other helix, in addition JOHN A. DOWDALL,

to the bodily movement of the armature by the A. W. FIsK. 

